Wrist lecture Flashcards
Which bones participate in the wrist/radiocarpal joint?
scaphoid, lunate, radius
What strengthens the joint capsule? On which aspects?
Radiocarpal ligaments anteriorly and posteriorly
What is the nerve supply of the intrinsic muscles of the hand?
ULNAR NERVE except thenar muscles and the 1st and 2nd lumbricals are the MEDIAN NERVE
What is the action of opponens pollicis?
Allows rotation of the thumb to grip against fingers (opposition.)
What is the action of the lumbricals?
flexion at metacarpophalangeal joints and extension the interphalangeal joints.
Of the muscles of the forearm, which are not supplied by the median nerve? What are they supplied by?
Flexor carpi ulnaris and the medial half of flexor digitorum profundus are supplied by the ulnar nerve.
What is in the thenar eminence?
Flexor pollicis brevis, opponens pollicis, abductor pollicis brevis
What is in the hypothenar eminence?
Opponens digiti minimi, flexor digiti minimi, abductor digiti minimi
How many dorsal interossei are there? What is their action?
4, abduction of fingers
How many palmar interossei are there? What is their action?
3, adduction of fingers.
What does the median nerve supply (motor) in the hand?
Thenar eminence, 1st and 2nd lumbricals
What is the most common carpal bone to dislocate? What are the consequences of this?
Lunate, similar symptoms to carpal tunnel if medial nerve is compressed.
What does the ulnar nerve supply?
Medial side of palm (palmer branch), digit 5 and half of digit 4, hypothenar muscles, adductor pollicis, interossei and 4th and 5th lumbricals.
Where does the ulnar nerve run in the wrist? With what?
Guyon’s canal with ulnar artery.
What does compression of the ulnar nerve at the wrist lead to?
Handlebar neuropathy. Sensory loss of palmar surface of digit 5 and half of 4. Motor weakness in intrinsic muscles of the hand (except thenar eminence and lateral 2 lumbricals). Hyperextension of metacarpophalangeal joints of digits 4 and 5 and clawing of these digits.
